@howardlee , it almost doesn’t matter what the subject is, the answers will range from "snake oil--it doesn’t have any effect on sonic performance" to "I hear a difference." Personally, I think it probably depends upon the speakers. If KEF or PSAudio provides any kind of tech support at all, it might be worth contacting them to find out what they think about b-wiring their speakers.
At the time I bi-wired I was running a pair of B&W 805s (the Matrix series) and I think B&W was saying that those speakers would benefit from bi-wiring. I felt that I heard an incremental improvement. At the time (going on 30 years ago) I was continuously trying to make upgrades and subtle improvements as I was into "the sum of all parts" theory, and I looked at bi-wiring as just another one of the parts.